Ctrcbit maker and breaker



Dec. 8, 1936. w. P. LOUDON CIRCUIT MAKER AND- BREAKER Filed March 12, 1951 W lhmcntor %/ZM Gttorncg Patented D... s, 1936 UNITED STATES PATENT OFFICE Warren P. London, Dayton, Ohio, assignor to Delco Aviation Corporation, Dayton, Ohio, a

corporation of Delaware l Application March 12, 1il31, Serial No. 522,037

8 Claims. This invention relates to ignition apparatus .and more particularly to circuit making and breaking mechanism employed in electrical ignition systems for internal combustion engines.

One of the objects of the present invention is to provide novel circuit making and breaking mechanism of the above character.

Another object of the invention is to provide in mechanism of the type referred to above, a novel arm or supporting structure for the movable and stationary contacts.

Still another object is to provide in a circuit making and breaking structure having relatively movable contacts, novel supporting means for the contacts whereby each contact is independently supported, the supporting means for the movable contact including a resilient arm, rigidly supported at one end.

Another object is to provide a novel supporting construction for the contacts of a circuit making and breaking mechanism including a resilient arm for the movable contact together with novel means for varying the tension of pressure between the contacts.

A further object is to provide in a device of the above character, independent supporting members for the contacts constructed and arranged in such a manner as to permit the adjustment of theinitial position of the stationary contact and also the pressure between the contacts.

A still further object is to provide a novel and improved light-weight circuit breaker mechanism embodyinga novel arrangement 01' parts whereby the contacts are not only readily accessible for inspection or repair, but are also so mounted as to be readily adjustabl both as to contact separation as well as contact pressure, thus insuring a unit which may be readily adapted for use with various types 'of engines.

The above and further objects will appear more fully from the following detailed description when taken in connection with the accompanying drawing, wherein one embodiment of the present invention is illustrated. It is to be expressly un-- derstood, however, that the drawing is for purposa' of illustration only and is not designed as a definition of the limits of the invention, reference being bad for this purpose to the appended claims.

, In the drawing, wherein like reference characters refer to similar parts throughout the several views:

Fig. 1 is a plan view of an ignition breaker embodying the principles of the present inventiqn;

the arm to adjust the- Fig. 2 is a perspective view of the movable contact-carrying arm and its \bracket;

Fig. 3 is a perspective view of-the parts constituting the supporting bracket-for the stationary contact; and

Fig. 4 is an enlarged detail, partly in section, taken on line 4-4 of Fig. 1.

Referring more particularly to the drawing, a circuit making and breaking mechanism embodying the present invention is illustrated therein as 10 comprising a metallic base plate 5, adapted to support movable and stationary contacts 6 and 1 respectively, in a manner to be more specifically referred to hereinafter, and these contacts are designed to be periodically actuated to open and 15 close the same by means of a cam 1 drivably connected to a suitable rotatable portion of an internal combustion engine and consequently rotating in timed relation therewith. The opening and closing of the contacts 5 and 6 is effective through suitable'circuits, not shown, to control 20 the ignition energy for igniting the combustible charges in the cylinders of the engine, as well understood in the art.

Novel means are provided by the present invention for supporting the movable contact and preferably such means are of the pivotless type. As shown, such means are constituted by a resilient leaf spring arm 8, one end of which is. rigidly secured to a supporting bracket or plate 9 by means of rivets Ill and I I, while the free end of the arm carries the contact Also secured to the bracket 8 is a resilient actuating arm, of

less length than the arm 8, and carrying at its outer free end, a cam follower or rubbing block l3 which is adapted to cooperate with the con tact-carrying arm 8 intermediate its ends and with the cam surface 1* to positively disengage the contacts.

Preferably the supporting structure for the 40 movable contact 1, referred to above, is adjustable in a direction perpendicular to the plane of engagement between the contacts in order to variably tension or flex the resilient arm 8 for varying the normal pressure between the contacts when the latter are closed. To this end, the bracket 9 is provided with a plurality {of elongated openings or slots-|4,,,the longitudinal axis of these openings being perpendicular to a plane including the surface of the contact 1 and these openings are adapted to receive holddown screws l5 which secure the brackets to the base plate 5. In the event that it is desired to move thebracket along the axis a-b, Fig. 2, it is only necessary toloosen screws l5, whereupon the bracket may be adjusted by reason of the slotted openings 14.

In order that the above-referred to movement of the bracket 5 may be effected in a simple and eilicient manner, a suitable cam member 16 is provided, said member having a shank l1, Fig. 4, rotatably carried by plate 5, and a cam surface l8. This cam surface is so proportioned as to be constantly in engagement with the sides is and 20 of a laterally disposed slotted opening 2| provided in the bracket 9, but spaced from either end of said opening. From the above it will be readily understood that upon loosening the screws i5 and rotating the member 16, the cam surface i3 will cooperate with the sides i3 and 20 of the opening 2! to move the bracket 9 along the line o-b in order to adjust the tension of the arm 8 and consequently the initial pressure between the movable and stationary contacts.

Novel means are provided for supporting the stationary contact and preferably such means are so constructed as to insulate this contact from the base plate. In the form of the invention illustrated, such supporting means are constituted by a metal supporting plate or bracket 22 adapted to be adjustably secured and grounded the base plate 5 and carrying a metal member 23 to which the contact 6 is secured, Fig. 3. interposed between members 22 and 23 is a metal member 24 to which a conducting strip 25 is secured in order to electrically connect the contact 8 with one terminal 26 of a condenser 21, suitably mounted on the base plate. An insulating member 28 is interposed between members 24 and 22 in order to insulate the stationary contact from the base plate 5 which is grounded. A suitable member 29 of insulating material is thereafter placed adjacent the opposite 'side of member 23, as shown, and the supporting means are completed with the metal plate 30. Thereafter, suitable holes 3| are drilled in assembled members 22, 28, 24, 23, 29 and 30 for the insertion of insulating sleeves 32 and the assembly is then secured together as by means of rivets 33. From the above it will be apparent that the stationary contact 5 is effectively insulated from the grounded base plate 5.

Means are provided for adjusting the stationary contact supporting member in a direction perpendicular to the plane of engagement of the contacts, in order to adjust the distance between the latter when open, and preferably such. means are constituted in a manner similar to the construction heretofore described in connection with the adjustment of the supporting means for the movable contact. As shown, the plate 22 is provided with slotted openings 34 for receiving screws 35, the longitudinal axes of said openings being parallel to each other, as indicated by the lines cd and e---), and perpendicular to a plane including the face of contact 6. A transversely extending slotted opening 33 provided in the bracket 22 is adapted to receive a cam member 31, similar to the cam member l3, and member 31 is operable to eifect adjustment of the initial or normal position of the stationary contact 8 by merely loosening the screws 35 and turning the cam member 31. The movement of the support will, as heretofore pointed out, be in the direction of lines cd and e-f, that is, perpendicular to a plane including the contacting surface of the contact 5. Adjustment in this manner will obviate the possibility of overlapping of the contacts in any position oi? adjustment.

In order to properly adjust the parts for most efhcient operation, the engine is first rotated, in any suitable manner, until one of the lobes of the cam 1 engages the cam follower I3 and moves the arm 8 upwardly, as viewed in Fig. 1, thus separating the contacts 6 and 1. The screws 35 may then be loosened, and the cam member 31 manipulated in such a manner as to adjust the initial position of the supporting plate 22 and stationary contact 6 carried thereby, in order to obtain the desired clearance between the contacts. The screws 35 are thereafter tightened, thus securing the plate 22 in its adjusted position. In order to obtain the proper pressure between the contacts, the engine is thereafter rotated in such a direction as to bring one of the flat portions of the cam 1 into engagement with the rubbing block 13, and the cam member I6 is thereafter rotated to effect movement of the supporting bracket 9 in such a direction as to insure the tensioning of the arm 8 to the desired degree to obtain the proper contact pressure, it being understood that the screws l5 are loosened prior in the adjustment of the cam member, and tightened after the adjustment has been completed. In operation, the lobes of the cam 1 will successively engage the cam follower i3 to effect periodic disengagement of the contacts while the resilient arm 8 will immediately cause engagement of the contacts as soon as the cam follower has passed over the lobes.

There is thus provided by the present invention a novel circuit making and breaking mechanism of the pivotless type wherein the movable arm is constituted by a light-weight resilient construction thus insuring successful and efllcient operation of the mechanism at high speeds. By supporting the movable contact at the free end of the movable resilientarm, the contact is rendered readily accessible for inspection or repair. Greater travel of the movable contact is obtained by actuating the movable arm intermediate its free end and supported end, thus enabling the use of a cam provided with small lobes and at the same time obtaining sufliclent separation of the contacts. By the provision of the independent supporting members for the stationary and movable contacts, adjustable in a direction perpendicular to the plane of engagement of the contacts, the position of the stationary contact may not only be readily adjusted to vary the clearance, but the contact pressure may also be readily varied for any desired condition of operation. It will also be observed that by providing a separate and independent support for the mo able contact, the construction of the same may be extremely simple inasmuch as it is only necessary to secure the same to a grounded member, thus avoiding all problems of insulation.

While there has been shown and described only one embodiment of the present invention, it is to be expressly understood that the same is not to be limited thereto but may be capable of expression in various mechanical forms, as well understood by those skilled in the art. Reference will therefore be had to the appended claims for a. definition of the limits of the invention.

What is claimed is:-

1. Ignition apparatus comprising a stationary contact, a movable contact cooperating therewith, means for supporting said stationary contact, separate means for supporting said movable contact, and means to adjust the pressure between said contacts comprising a device for moving said last named supporting means bodily and independently of said first named supporting means and in.a direction perpendicular to the plane of engagement ,between said contacts.

2. In combination with a pair of relatively movable contacts said contacts having a plane engaging surface, separate means for supporting each of said contacts, and means for adjusting each of said supporting means in a direction at right angles to the plane of engagement between said contacts, said adjusting means including a cam member for each of said supporting means and cooperating therewith.

3. Ignition apparatus comprising a pair of normally engaged relatively movable contacts, an actuating cam operatively associated with one of said contacts, a leaf spring for supporting said one of said contacts, means for supporting the other of said contacts, and means independent of said cam-to adjust pressure between said contacts comprising a device for moving said spring bodily and independently of said last named supporting means and in a direction at right angles to the plane of engagement between said contacts.

' ,4..Ignition apparatus comprising a pair of relatively movable normally engaged contacts, a

separate bracket for supporting each contact, a leaf spring rigidly secured at one end thereof to one of said brackets and carrying one of said contacts at the free end thereof, and means including a pivoted cam member cooperating with said last-named bracket for moving the latter in a direction perpendicular to the plane of engagement between said contacts to'adjust the pressure therebetween.

e 5. Ignition apparatus comprising normally ehgaged movable and stationary contacts, and means for causing relative movement 01' said contacts said means including a pair of leai spring arms each of which is rigidly supported at one end thereof independently of the other, one of said arms carrying the movable contact, and

means for operatively connecting the other of said armsto said first-named arm between the contact and the rigidly supported end thereof.

6. Ignition apparatus comprising a stationary contact, a movable contact cooperating therewith, means for supporting said stationary contact, means for supporting said movable contact comprising a bracket and a resilient arm fixedly secured to said bracket at one end thereof and carrying the movable contact at the other end thereof, and means for moving said bracket in a direction perpendicular to the planeof engagement between said contacts to adjust the pressure therebetween.

7. In combination with a pair of normally engaged movable and stationary contacts, independent means for supporting each of said contacts, the means for supporting the movable contact including a resilient non-pivoted arm, and means for adjusting each of said supporting means independently of the other in a direction perpendicular to the plane of engagement between said contacts.

8. In combination with a pair ,of relatively movable contacts said contacts having a plane engaging surface, means for supporting one of said contacts, means including a resilient arm .for supporting the other of said contacts, and means for adjusting each of said supporting 

